In its most general form, a playlist is simply a list of songs. The term has several specialized meanings in the realms of radio broadcasting and personal computers.

The term originally came about in the early days of top 40 radio formats when stations would devise (and, eventually, publish) a limited list of songs to be played. The term would go on to refer to the entire catalog of songs that a given radio station (of any format) would draw from. Additionally, the term was used to refer to an ordered list of songs played during a given time period. Playlists are often adjusted based on time of day, known as dayparting.

As music storage and playback using personal computers became common, the term playlist was adopted by various media player software programs intended to organize and control music on a PC. Such playlists may be defined, stored, and selected to run either in sequence or, if a random playlist function is selected, in a random order. Playlists' uses include allowing a particular desired musical atmosphere to be created and maintained without constant user interaction, or to allow a variety of different styles of music be played, again without maintenance.

Some websites allow categorization, editing, and listening of playlists online, such as Project Playlist, Plurn, imeem and Webjay. Other sites such as Musicmobs focus on playlist creation aided by personalized song recommendations, ratings and reviews. On certain sites, users create and share annotated playlists, giving visitors the option to read contextual information or reviewer comments about each song while listening. Some sites only allow the sharing of the playlist data with the actual music being delivered by other channels e.g. plurn, others provide a closed catalog of content from which the playlists can be generated while sites like imeem allow users to upload the music to central servers to be shared and accessed by any user of the site.

Celebrity playlist

A list of songs prepared by a celebrity and represented on the Apple iTunes Store as such, is referred to as a "celebrity playlist". This has become popular because a fan of a particular celebrity may have an affinity towards the celebrity's choice of music. This arms-length connection between the fan and the favored celebrity has become so popular (2004-2005) that "celebrity playlist" has become a part of recent vocabulary.

Shuffle mode playlists

Sometimes playlists are devised for the sake of curbing shuffle play to music that fits in better with the setting (e.g. party, dance, etc.).

Other playlist methods

• A CD player that holds multiple CDs with a programmable grid mapper.
• MP3 CDs
• Prerecording a mixtape; which is purely sequential.
• Active disc-jockeying where the user manually selects the next song one after another as opposed to a preprogrammed playlist (shuffled or not).
• A jukebox with a programmable vinyl record changer

Types of playlist files

There are several types of playlists. Some of the most common are:

• .asx, an XML style playlist containing more information about the items on the playlist.
• .bio, a text-based list of items, with each item on a new line. Each item represents the full path to the file.
• .m3u, a simple text-based list of the locations of the items, with each item on a new line.
• PLC, file extension for AIMP2 media player
• .pls, a text playlist similar to .ini (program settings) files. It normally contains only the location of the items in the playlist.
• .smil is an XML recommendation of the World Wide Web Consortium that includes playlist features. In addition to audio, it supports video and screen layout and is heavily used in Digital Signage.
• Kalliope PlayList (.kpl) is a kind of XML playlist storing developed to speed up loading and managing playlists.
• .pla, Samsung format(?), binary, Winamp handles these
• XSPF, an XML format designed to enable playlist sharing.
• VLC is a format used by VLC Media Player.
• WPL is an XML format used in Microsoft Windows Media Player versions 9–11.
• ZPL is an format used by Zoom Player and Creative Zen Media Players.
• FPL is a format used by Foobar2000.

See also

• Mixtape
• Music scheduling system
• Shuffle play
• Playlist markup language